CVE-2024-7983: Open WebUI unauthenticated DoS

Q: Is CVE-2024-7983 actively exploited?

No confirmed active exploitation of CVE-2024-7983 has been reported, but organizations should still patch proactively.

Q: How to fix CVE-2024-7983?

1. PATCH: Upgrade open-webui beyond version 0.3.8 — verify a fixed release is available before upgrading. 2. NETWORK CONTROL (interim): Restrict access to the markdown conversion endpoint (`/api/utils/markdown`) via WAF rule or reverse proxy — block or require authentication on this specific route. 3. RATE LIMITING: Add rate limiting at the reverse proxy level (nginx/Caddy) for all unauthenticated API endpoints. 4. DETECTION: Monitor for requests to the markdown endpoint with unusually large payloads or long processing times; alert on server response time degradation. 5. NETWORK HARDENING: If open-webui is for internal use only, ensure it is not exposed to the public internet — enforce authentication at the network perimeter.

Q: What systems are affected by CVE-2024-7983?

This vulnerability affects the following AI/ML architecture patterns: LLM chat interfaces, self-hosted AI platforms, AI model serving, agent frameworks.

Q: What is the CVSS score for CVE-2024-7983?

CVE-2024-7983 has a CVSS v3.1 base score of 7.5 (HIGH). The EPSS exploitation probability is 0.81%.

CISO Take

An unauthenticated endpoint in open-webui ≤0.3.8 allows any network-reachable attacker to hang the server by sending a malicious markdown payload, denying LLM access to all users until the request completes. If your team uses open-webui as a self-hosted LLM interface, treat this as a single-request availability kill switch — no credentials required. Patch immediately or firewall the markdown conversion endpoint as an interim control.

What is the risk?

CVSS 7.5 High, but EPSS of 0.16% indicates limited active exploitation observed. Exploitability is trivially low-barrier: network access + one HTTP request, no authentication or AI/ML knowledge needed. Blast radius is availability-only (C:N/I:N/A:H) — no data exfiltration risk. The primary concern is deployment context: open-webui instances exposed to untrusted networks (internal threat actors, exposed dev environments) face meaningful availability risk. The lack of a patch version listed increases urgency.

What systems are affected?

Package	Ecosystem	Vulnerable Range	Patched
Open WebUI	pip	<= 0.3.8	No patch
142.4K Pushed 4d ago 77% patched ~5d to patch Full package profile →

Do you use Open WebUI? You're affected.

How severe is it?

CVSS 3.1

7.5 / 10

EPSS

0.8%

chance of exploitation in 30 days

Higher than 52% of all CVEs

Source: EPSS v3 — FIRST.org

Exploitation Status

Exploit Available

Exploitation: MEDIUM

Sophistication

Trivial

Exploitation Confidence

medium

○ CISA SSVC: Public PoC

Composite signal derived from CISA KEV, VulnCheck KEV, CISA SSVC, EPSS, Metasploit, Exploit-DB, trickest/cve, Nuclei templates, and inthewild.io exploitation reports.

What is the attack surface?

AV Network

AC Low

PR None

UI None

S Unchanged

C None

I None

A High

What should I do?

5 steps

PATCH

Upgrade open-webui beyond version 0.3.8 — verify a fixed release is available before upgrading.
NETWORK CONTROL (interim): Restrict access to the markdown conversion endpoint (/api/utils/markdown) via WAF rule or reverse proxy — block or require authentication on this specific route.
RATE LIMITING

Add rate limiting at the reverse proxy level (nginx/Caddy) for all unauthenticated API endpoints.
DETECTION

Monitor for requests to the markdown endpoint with unusually large payloads or long processing times; alert on server response time degradation.
NETWORK HARDENING

If open-webui is for internal use only, ensure it is not exposed to the public internet — enforce authentication at the network perimeter.

What does CISA's SSVC say?

Decision Track*

Exploitation poc

Automatable Yes

Technical Impact partial

Source: CISA Vulnrichment (SSVC v2.0). Decision based on the CISA Coordinator decision tree.

How is it classified?

DoS Auth Bypass API Framework AML.T0029 - Denial of AI Service AML.T0034 - Cost Harvesting AML.T0049 - Exploit Public-Facing Application

Which compliance frameworks are affected?

This CVE is relevant to:

EU AI Act

Art. 9 - Risk Management System

ISO 42001

A.6.2.6 - Security of AI system inputs

NIST AI RMF

MANAGE 2.2 - Mechanisms for sustaining operational resilience

OWASP LLM Top 10

LLM04 - Model Denial of Service

Frequently Asked Questions

What is CVE-2024-7983?

An unauthenticated endpoint in open-webui ≤0.3.8 allows any network-reachable attacker to hang the server by sending a malicious markdown payload, denying LLM access to all users until the request completes. If your team uses open-webui as a self-hosted LLM interface, treat this as a single-request availability kill switch — no credentials required. Patch immediately or firewall the markdown conversion endpoint as an interim control.

Is CVE-2024-7983 actively exploited?

No confirmed active exploitation of CVE-2024-7983 has been reported, but organizations should still patch proactively.

How to fix CVE-2024-7983?

1. PATCH: Upgrade open-webui beyond version 0.3.8 — verify a fixed release is available before upgrading. 2. NETWORK CONTROL (interim): Restrict access to the markdown conversion endpoint (`/api/utils/markdown`) via WAF rule or reverse proxy — block or require authentication on this specific route. 3. RATE LIMITING: Add rate limiting at the reverse proxy level (nginx/Caddy) for all unauthenticated API endpoints. 4. DETECTION: Monitor for requests to the markdown endpoint with unusually large payloads or long processing times; alert on server response time degradation. 5. NETWORK HARDENING: If open-webui is for internal use only, ensure it is not exposed to the public internet — enforce authentication at the network perimeter.

What systems are affected by CVE-2024-7983?

This vulnerability affects the following AI/ML architecture patterns: LLM chat interfaces, self-hosted AI platforms, AI model serving, agent frameworks.

What is the CVSS score for CVE-2024-7983?

CVE-2024-7983 has a CVSS v3.1 base score of 7.5 (HIGH). The EPSS exploitation probability is 0.81%.

What is the AI security impact?

Affected AI Architectures

LLM chat interfacesself-hosted AI platformsAI model servingagent frameworks

MITRE ATLAS Techniques

AML.T0029 Denial of AI Service

AML.T0034 Cost Harvesting

AML.T0049 Exploit Public-Facing Application

Compliance Controls Affected

EU AI Act: Art. 9

ISO 42001: A.6.2.6

NIST AI RMF: MANAGE 2.2

OWASP LLM Top 10: LLM04

What are the technical details?

Original Advisory

In version 0.3.8 of open-webui, an endpoint for converting markdown to HTML is exposed without authentication. A maliciously crafted markdown payload can cause the server to spend excessive time converting it, leading to a denial of service. The server becomes unresponsive to other requests until the conversion is complete.

Exploitation Scenario

An adversary discovers an open-webui instance via Shodan or passive DNS reconnaissance. Without any credentials, they craft a markdown payload designed to trigger catastrophic backtracking in the regex-based parser (e.g., deeply nested markdown structures, malformed tables, or pathologically complex inline formatting). A single POST to the unauthenticated markdown-to-HTML endpoint causes the server process to peg CPU for an extended period. Legitimate users attempting to interact with the LLM receive timeouts or connection failures for the duration. The attacker can sustain the outage by sending repeated requests, effectively maintaining a denial of service with minimal effort and no authentication. In AI-assisted operations environments (SOC tooling, developer assistants), this disrupts AI-augmented workflows during the outage window.

Weaknesses (CWE)

CWE-400 Uncontrolled Resource Consumption Primary CWE-770 Allocation of Resources Without Limits or Throttling Primary

CWE-400 — Uncontrolled Resource Consumption: The product does not properly control the allocation and maintenance of a limited resource.

[Architecture and Design] Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
[Architecture and Design] Mitigation of resource exhaustion attacks requires that the target system either: The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker. recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.

Source: MITRE CWE corpus.